Control for pneuamtic stratification separator



Nov. 27, 1962 D. B. BINNIX 3,065,853

CONTROL FOR PNEUMATIC STRATIFICATION SEPARATOR Filed Jan 27, 1961 3Sheets-Sheet 1 I H/sArranA/Y Nov. 27, 1962 D. B. BINNIX 3,065,853

CONTROL FOR PNEUMATIC STRATIFICATION SEPARATOR Filed Jan 2'() 1961 5Sheets-Sheet 2 IN VENTOR. Dau/Ma. M/N/x 'H/.s A rraawsv Nov. 27, 1962 D.B. BlNNlx 3,065,853 CONTROL FOR PNEUMATIO STRATIFICATION SEPARATOR FiledJan 271961 3 Sheets-Sheet 3 IN V EN TOR. Douma B. /umx H15 ArraeusyrUnited States Patent Oiiice 3,365,853 Patented Nov. 27, 1962 3,065,853CNTROL FOR PNEUMATIC STRATHFCATON SEPARATR Donald B. Binnix, RidgeEquipment Co., Fallentimber, Pa. Filed Jan. 27, 1961, Ser. No. 85,318 15Claims. (Cl. 2i9-463) This invention relates generally to the separationof minerals by pneumatic stratiiication and more particularly to animproved method of control of a stratification separator.

Pneumatic stratication of minerals such as coal presents many problemsin the smooth operation of the separator apparatus when subjected tocontinuous changing of the waste loads presenting a vast difference inthe amount of slate and other impurities. The machine becomes adjustedto ore percentage of waste and the next load has a materially dilerent-amount of bone, slate and other waste. It takes a few minutes for thepneumatic pressure to become effective.

The principal object of this invention is the provision of an addedcontrol to aid the separator to more quickly respond to such rapidchanges.V

Another object is the provision of a sensitive pneumatic pressurecontrol to operate the refuse gate opening in accordance with theresistance to llow of air through the last portion or sections of thepneumatically suspended bed by quickly bleeding olf a portion of the airflowing to that section of the bed to decrease the pressure and preventthe control from overcarrying its operation in the amount it opens therefuse gate. The buildup of the heavier waste material adjacent thelower end of the pneumatically suspended bed causes the pressure tobuild up which actuates the waste discharge gate by a pneumaticservomotor such `as a diaphragm type. The resistance to flow readilybuilds up in the air duct and operates the servomotor. This action canbe too impulsive and to temper the same a portion of the air underpressure may bedischarged continuously or intermittently during thisperiod either manually or automatically.

Another object is the provision of a manual valve for exhausting aportion of the air supplied to the last two cells which pneumaticallytloats the material to be separated just prior to the dam that selectsthe denser strata to be discharged to enable manual manipulation of thepressure where the pneumatically iloated bed is heaviest and lessimpenetrable requiring greater pneumatic pressures. By observing themovement of the pneumatically suspended bed through a transparentplastic side, such as glass or methametharylic, one can judge when theair should be bled a little to be more effective in continuouslydischarging the waste product.

Another object is the provision lof an automatic valve for discharging aportion of the air under pressure that is suspending the last portion ofa pneumatically suspended stratiiication bed just prior to discharge.

Other objectsA and advantages of this invention appear hereinafter inthe following description and claims.

The accompanying drawings show for the purpose of exemplication withoutlimiting this invention or the claims thereto, certain practicalembodiments illustrating the principles of this invention; wherein FIG.1 is a View in side elevation with parts in section showing thepneumatic stratier comprising this invention. l FIG. 2 is a view in sideelevation illustrating the blowlers attached to the left end of themachine shown in FIG. 1.

FIG. 3 is a detailed view in partial section showing a manually operatedvalve for controlling the partial discharge of the pneumatic pressurefrom the last portion of the suspended bed.

FIG. 4 is a detailed view in partial section showing an automaticallyoperated valve for controlling the partial discharge of the pneumaticpressure from the last portion of the suspended bed.

Referring to FIG. 1 of the drawings the pneumatic stratiiier comprisesthe enclosure 1 being separated in ve diiferent chambers, the materialchamber 2 the bottom of which contains the sloping pneumatic screen 3,the second chamber 4 containing a series of cells 5 which separate theunder side of the screen 3 in seven cells for the first section 6, forthe second section 7 there are six cells 5 and in the third section 8there are two cells. The third chamber is a pneumatic chamber 10 thatsupplies the air to the irst section 6 of the cells 5. The fourthchamber 11 is a pneumatic chamber that supplies air to the secondsection 7 of the cells 5 and the fth chamber 12 is a pneumatic chamberthat supplies air to the last two cells in the section S. Thus each ofthe live chambers within the enclosure 1 provides a function to increasethe volume and pressure of the air downwardly along the pneumatic screenSto the discharge end.

Chamber 2 is supplied with a mineral such as run of the mine coal whichis preferably sized from zero to three-quarter inch that is dumped inthe hopper 13, the hopper gate 14 of which is adjustably positioned bythe operating handle 15. The limitations of the movement of the gate 14are shown in the drawing.

The coal proceeds down into the chamber 2 and along the screen 3 andeach cell 5 under the screen is divided into two sections, the topsection that contains a marble pack which consists of a pack of glassmarbles 16 that diffuse the air owing upwardly through the cell andthrough the screen 3 to suspend the coal and stratiiy the same. Themarbles 16 are supported on a large screen mesh 17 and the marble packor bed will vary in depth in the consecutive cells from the beginning ofthe screen to the discharge thereof. More marbles are provided in theinitial cells than in the end cells because the marbles have the effectof not only diffusing the air but `also diminishing the volume andpressure of the air to the screen 3 as the pack is increased in depth.Each cell also contains a manually operated vane or valve 18 pivoted onthe shafts 20 and provided with `an indicator such as shown at 21. Thevanes or valves 18 are employed to also regulate the amount of airadmitted to each cell. Thus the adjustment of the vanes or valves 18together with the depth of the marble pack are determining factors inthe amount of air that is admitted to that section of the screen 3supplied by each particular cell S for determining the pneumaticsuspension of the body of material such as coal.

When the run of mine coal enters this stratifier the particles ofheavier specific gravity such as slate and rock and sulphur balls andthe like are interspersed throughout the material but as the material issuspended by the air these heavier particles drop to the lower part ofthe screen; Whereas the lighter coal particles stay at the top of thebed of pneumatically suspended coal. As the bed moves down the screenthe heavier parts all collect at the underside of the bed close to thescreen and become very dense which requires a greater volume of air anda higher pressure of air to suspend the bed which is compensated for byseparating the chambers 10, 11 and 12.

As the bed reaches the cells 22 and 23, a special screen is provided asindicated at 24 over these cells and which permits the entry of -3/16reject off the bottom of the suspended coal bed moving thereunder. Theserejects are the heavy particles initially separated out from the bed andhave not had a suiiicient time to become too dense and therefore aremore readily removed through and is conveyed laterally by the screw Z8.It these -3/16" rejects were permitted to be conveyed further along thepneumatically suspended bed of coal the increased air pressure from thispoint on would have the tendency of sending these ten mesh rejectshigher in the pneumatically suspended coal bed and thus create acondition where it would be diicult to insure the removal of a highpercentage of the ?G rejects at the end of the bed. The separation istherefore improved by this intermediate draw-off of the -3715 rejectsbefore the air volume and pressure becomes too high to cause theserejects to intermingle with the coal. It will be noted that the cells 22and 23 are at the end of the air chamber which is the rst chamber of thesystem. The chamber 10 is supplied with air through the rotary valve 30which is driven by the variable speed motor 31 and reducer mechanismthrough a chain 32. A second chain 33 drives the lower rotary valve 34.The rotary valves and 34 are the same and have spherical plug members asindicated at 35 with a central passageway 36. The spherical portion ofthe plug 35 of the valve cooperate with the adjustable port members 37of which there are four. It will be noted in the drawings that the samemotor driving the two rotary valves 30 and 34 control the movement ofair therethrough at 180 out of phase from each other as the part 36 ofthe upper valve plug is shown in a horizontal position while the port 36of the lower valve plug is shown in vertical position. In other words,while the valve 30 has its passage 36 so as to let the maximum amount ofair from the chamber 38 to the chamber 10 as shown, the valve 34 closesand prevents any passage of air from the chamber 38 to the chamber 11.Thus upon the rotation of both of the valves 30 and 34 the air supplied'to the cells 5 is pulsated according to the revolutions per minute ofthe rotary valves and since these valves are operated simultaneously butat 180 out of phase with each other, the pulsation of air inpneumatically suspending the initial portion of the coal bed is also 180out of phase than the second portion which is indicated by that portionof the pneumatically suspended coal over the cell 7 fed by the chamber11. These pulsations not only aid in the suspension of the bed butprovide a movement that allows the particles making up the coal rbed toarrange themselves in stratification throughout the depth of the bed inaccordance with the specific gravity of each of the particles. Thus notonly the size and depth of the marbles in the marble pack 16 but alsothe adjustment of the valves or vanes 18 function to pneumaticallysuspend the coal bed but the number of air pulsations created by therotary valves 30 and 34 likewise have an effect in the pneumaticsuspension of the coal bed that permits the particles of differentspecific gravity to reach their own level within the bed. This too iffurther affected by the size and the number of cells pulsated by each ofthe valves. One thus has many Variables which may be adjusted to providean improved pneumatic suspension of the coal bed.

The chamber 38 as shown in FIG. 2 is supplied with air from the fanindicated at 40 which is in turn driven by a motor 41. The chamber 12 inturn is supplied with air from the fan 42 driven by the motor 43. Themotors 41 and 43 are likewise variable in speed so as to permit achamber in the volume of air produced over a given time which is a sixthfactor in the control of the supply of air to pneumatically suspend thebed of coal which is thus caused to move down the sloping screen 3 dueto gravity and because of this pneumatic pulsating suspension.

The chamber 12 is provided with the rotary valve member 44 which is asingle bladed valve that imparts two pulsations per revolution from thechamber 12 to the end cells 45 and 46. The valve 44 is driven by meansof the variable speed motor and reducer 47 and this motor is alsoemployedv to drive the screw conveyor 2S as shown.

Thus not only each of the consecutive cells 5 all the way down thescreen 3 provide for the passage of an increased volume of airprogressively down the screen but the last two cells require aconsiderably greater amount of air than the cells in the chamber 7because the bed of coal by this time is substantially all properlystratified 4with the heavy specific gravity rejects lying along thebottom portion of the bed being substantially uniform in depth and theair supplied through the cells 45 and 46 of the chamber 8 must bematerially greater in volume to pulsate the bed at this position forwhich reason the chamber 8 is supplied with air from an independentsource.

At the end of the chamber 2 a discharge chute 50 which is rather steepin its inclination has a lip or dam 51 at its upper end. This dam hasupper and lower projections 52 and 53 that fit on the top and bottom ofthe chute 50 which permit the dam member 51 to be removable and changedfor different types of run of the mine coal. It will be noted that thebottom edge of the dam is spaced from the screen 3 and' this spacingpermits the ow of the reject material from the under side of thestratiiied bed; whereas the coal will flow over the top of the dam 51and pass down the chute 50 cleaned of all of its reject. The chute 50rests on the cam 54 which is mounted on the shaft 55 rotated by the handlever 56. Thus different positions of the lever 56 will cause the cam 54to vary the height of the chute 50 and thus the opening between the-bottom edge of the dam 51 and the screen. A stop 57 prevents the member58 on the shaft 55 to limit the movement of the lever and the spring 60is attached to the lever 56 to maintain the movable abutment 58 againstthe stop 57 and thus at all times maintain a constant opening betweenthe bottom of the dam 51 and the screen 3. If for some reason a largechunk of material descends in the pneumatically suspended bed and tendsto clog this opening under the dam one need only to depress the lever 56and the cam 54 will raise the chute 50 and the dam to permit the largepiece that is blocking the dam to pass therethrough to reject. The mererelease of the handle 56 causes the spring 60 to move into its iixedposition against the stop 57.

The air chamber has exposed thereto a servomotor of pneumatic typecontaining a exible diaphragm 61 which is fastened between the annularrings 62 and the center of the diaphragm is provided with the plates 63which permit it to be attached by the link 64 to the lever 65. The lever65 is fulcrumed at 66 and its other end is provlded with the link 67that connects to the second lever 68 of the system. The link 67 may beadjusted along the levers 65 and 68 to provide for different weights ofthe reject material. The end of the lever 68 is supported by the spring70 and its intermediate portion is fulcrumed as indicated at 71. Thisfulcrum can be changed' in its position along the lever 68 by means ofthe many holes provided. Thus the lever 68 is adjustable relative to thelever 65 as well as the link 67.

The fulcrum 71 of the lever 68 carries the refuse gate 72 which receivesall the refuse that flows under the dam 51. The refuse is held on thegate by reason of the lever system and is opened only when the aireffective on the diaphragm 61 is of suicient pressure which indicatesthat it is having a very diflicult time pneumatically suspending the bedof coal just above the dam 51. As the reject strata in the coal bed onthe screen 3 becomes very dense, the pressure in the chamber 12increases. This dense material is of course a measurement of the weightof the reject and since the high density creates an increased pressureon the disphragm 61 the lever 65 will be rotated clockwise and pull thelever 68 against the tension of the spring 70 and will open the gate 72and allow more or less reject to ow from the end of the screen 3.

The pulsating air pressure in the chamber 12 is eifective to vibrate thelever system in the period of the pulsations of air which vibrationmakes the lever system sensitive to slight variations in pressure andthe gate 72 is thereby maintained open to the proper amount for the exitof the reject at a speed correlated with the density of the reject inthe last portion of the screen. In this manner a very high degree ofaccuracy is maintained in the separation of reject from the coal by thisgaseous suspension stratier.

The sides 73 of the chamber 2 may be made of a clear plastic when thestratier is employed for the separation of rejects from coal. Suchplastic side walls may be made of methyl methacrylate and will last aconsiderable length of time which is rather diiicult to understand asone would think that such a material would become scratched by the coalandother particles traveling therethrough.- However, the methylmethacrylate is found to stand up far better than that of glass which ismuch harder and it permits the operator to frequently view thestratication ofthel reject in the pneumatically suspended pulsating coalbed. It is believed that the plastic is lubricated by the coal and doesnot set up a charge that will hold the dust particles which permits thebed to be readily observed through plastic rather than through glass.

The lateral throat 74 connecting the chamber for the diaphragm 61 hasthe valve opening 75 on one side thereof which is closed by the valve 76attached to the valve bell crank lever 77 having a fulcrum at 78 andcarrying a poise 80. The poise is adjustable along the horizontallydisposed arm of the bell crank 77 in the manner of that of a beambalance. The pressure that the poise exerts on the valve opposes theinternal pneumatic pressure of the fifth chamber 12. Thus the area ofthe valve 76 that is exposed together with the weight of the bell crankand poise must be calibrated against the air pressures built up in thechamber 12 for different coal having varying amounts of bone, slate andother waste. This bell crank arm is also readily operable by hand.

It should be noted that the valve 76 is out of the way of the path offlow of air so that the actual movement of air is ineffective on thevalve.

Referring to FIG. 3 the lateral chamber 74 has the pipe 81 connectedthereto which is provided with a valve 82 having a discharge pipe 83.Thus an operator can watch the action of the suspended bed and operatethe valve 82 to obtain the best percentage of Waste floatation. Thevalve 82 may be set manually every so often. One could of course do thesame by lifting the arm 77 of FIG. 1 but the same adjustment wouldprevail when the operator allowed the arm 77 to return.

Referring to FIG. 4 the valve 84 is of the butterfly type and this valveis actuated through the arm 85 and the link 86 and the arm 87 by theservomotor 88 which in turn is actuated by the presence Variationsobtained through the pipe means 89, the pressure responsive means 90which in turn is connected by the pipe means 91 with the chamber 12closely adjacent the cell chambers 45 and 46. Through these instrumentsthe valve 84 may be regulated by relative changes in the pulsatingpneumatic pressures to properly proportion the discharge of the air fromthe chamber 12 to overcome too active or over regulating the operationof the valve 72. At the same time the full air supply and appropriatepressure remains available of use.

I claim:

1. The method of cleaning minerals which comprises the steps ofsuspending a downwardly sloping mineral bed by applying a pulsatingpneumatic pressure upwardly therethrough for its full length of themineral bed to move it downwardly, providing a gradation of increasedpneumatic pressure along the downwardly sloping mineral bed to stratifyand maintain the suspended particles stratified according to theirspecic gravity, separating the stratiied layers at the end of themineral bed as the sloping mineral bed continues to move, restrainingthe movement of the separated particles having heavier specific gravityto control the movement of the unseparated particles of heavier specicgravity, and discharging from the system to atmosphere a portion of theincreased pneumatic pressure from adjacent the lower end of the mineralbed to prevent the control from overcarrying the operation indischarging the separated particles of heavier specific gravity.

2. The method of claim l characterized by manually controlling thedischarge of the portion of the increased pneumatic pressure fromadjacent the lower end of the bed.

3. The method of claim 1 characterized by automatically controlling thedischarge of the portion of the increased pneumatic pressure fromadjacent the lower end of the bed in accordance with the pressuredeveloped toV suspend the lower end of the bed.

4. The method -of claim 3 characterized by balancing thev pneumaticpressure against a predetermined load to proportion the control of thepartial pneumatic discharge.

5. The method of claim 3 characterized by proportioning the control ofthe par-tial pneumatic discharge by relative changes in the pulsa-tingpneumatic pressure.

6. A machine for pneuma-tically stratifying a mineral bed whichcomprises a downwardly sloping screen having a discharge at its lowerend, a stra-tication separator means at said discharge, a plurality ofdivisible sections disposed in series along the underside -of saidscreen, dividing means to independently isolate from each other aplurality of said divisible sections in different chambers, means forsupplying dilerent and independent pneumatic pressures in selected ofsaid chambers, a rotary valve means in each of said chambers to createpulsations in the pneumatic fluid delivered under pressure thereto, andpneumatic pressure discharge valve means connecting at least one chambersupplying pulsating pneumatic pressure to the sections adjacent saidmineral discharge to atmosphere.

7. The structure of claim 6 characterized in that said :last mentionedvalve means is manually operated.

8. The structure of claim 6 characterized in that said last mentionedvalve means is pivotally Isupported and presen-ts a predetermined areato said chamber, and poise to apply a predetermined Weight to said lastmentioned valve means.

9. The structure of claim 6 characterized in that said -last mentionedvalve means is actuated by a pressure responsive means controlled fromthe pressure developed in said chamber.

l0. The method of cleaning minerals lwhich comprises the steps ofsuspending a downwardly sloping mineral bed yby applying independentpulsating pneumatic pressure upwardly through different portions of -themineral bed to move it downwardly to separate the stratified layersadjacent the lower end of the mineral bed as the bed continues to move,restraining vthe movement of the separated particles of heavier specificgravity at .the lower end of the mineral bed, controlling the dischargeof lthe separated par-ticles having heavier specic gravity at the lowerend of the bed in accordance with the independently isolated pneumaticpressure at the lower end of the bed, and independently exhausting toatmosphere a portion of the independently isolated pneumatic pressurefrom adjacent the lower end of the mineral bed to prevent theoverrunning of the control in operating the discharge of the separatedparticles having heavier specific gravity.

11. The method of cleaning minerals which comprises the steps ofsuspending a downwardly sloping mineral bed by applying pulsatingpneumatic pressure upwardly therethrough for lthe full length of themineral bed t0 move i-t downwardly to separa-te the stratified layersadjacent .the lower end of the mineral .bed as .the bed continues tomove, restraining the movement of the separated particles of heavierspecic gravity at the tlower end of the mineral bed, controllin-g thedischarge of the separa-ted particles having heavier specific gravity atthe lower end of .the bed in accordance with lthe pneumatic pressuresuspending the mineral bed, and independently exhausting to atmosphere aportion of the pneumatic pressure to prevent the overrunning of thecontrol in operating the discharge of the separated particles havingheavier specific gravity.

12. A machine for pneumatically stratifying a mineral =bed whichcomprises a downwardly sloping screen having a discharge at its lowerend, means for supplying a gnadation of increased pulsating pneumaticpressure along the downwardly sloping mineral bed to stratify andmaintain the suspended particles stratied according to their specificgravity, stratification 1separator means at said discharge,pneumatically operated pressure control means to actuate saidstratication separator means to restrain the movement of the separa-tedparticles having heavier specic gravity and control .the stratiiication,and valve means connected to discharge a portion of the pulsa-tingpneumatic pressure to atmosphere to prevent said pneumatic pressurecontrol means actuating said stratification separator means fromoverrunning the operation -thereof in discharging the particles ofheavier specific gravity.

13. The pneumatic stratier of claim 12 characterized in that said lastmentioned valve means is manually operated.

14. The pneumatic stratier of claim l2 characterized in that said lastmentioned valve means is pivotally supported and presents apredetermined area exposed to the pulsating pneumatic pressure, and abalance arm having a poise to apply a predetermined weight to saidpivotally supported valve means.

15. 'Ihe pneumatic stratier of claim 12 characterized in that said lastmentioned valve means includes a pressure responsive means controlledfrom the pulsating pneumatic pressure suspending the mineral bed tocontrol the discharge `of the pulsating pneumatic pressure.

References Cited in the le of this patent UNITED STATES PATENTS2,245,942 Stump June 17, 1941 FOREIGN PATENTS 610,499 Germany 1932619,976 Germany 1935 804,931 France Apr. 10, 1936

